Crusher



Oct: 13, 1925- B. A. MITCHELL,

causann Filedbec. 8. 1 921 I 3 "sham-sum i= I INVENTQR ATTORtiEY I Oct e cnusami v Filed Dec. 8, 1921 3 Sheets-Sheet 5 INVENTQR ATTORNEY Patented Oct. 13,1925.

.UNITED' STATES PATENT OFFICE.

BENJAMIN A. MITCHELL, OF WESTERLEIGH, NEW YORK.

CBUSHER.

Application filed December 8, 1921'. Serial No. 520,794.

To all whom it may concern:

' Be it known that I, BENJAMIN A. Micron- ELL, a citizen of the United States, reslding at T/Vesterleigh, Staten Island, in the county of Richmond and State of New York, hav invented certain new and useful Improvements in Crushers, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same. a

This invention relates to crushers for crushing stone, rock, ore, and the like and.

more particularly to crushers in which the moving crusher member is actuated by a rotating system.

This invention has for its general object an improved construction and arrangement of parts which is durable, efficient in operation, and readily manufactured.

A more specific object of this invention is to provide an arrangement designed to increase the capacity of crushers for a given input of power and to improve the nature of the crushing action. Another object is to mount and arrange the crusher members relativelyiso that side thrust,'strains, and friction are greatly minimized or substantially eliminated.

Another object'i's to improve the mechanical arrangement employed for transmitting motion from a rotating system to the movable crusher member.

Another object is to provide an arrangement of crusher parts in which centrifugal force is employed as the crushing agent,

thereby utilizing in crushers what was here-.

tofore a destructive force.

Another object is to employ a balanced rotating system in crusher construction in order that higher angular velocities may be utilizedin the rotating system than heretofore, thereby materially increasing outputs forgiven inputs of power.

Other'objects and adva-ntageswill in part be specifically pointed out hereinafter and in part obvious from the arrangements and constructions here set forth.

The'in'vention accordingly consists in the features of construction, combinations of elements and arrangement of parts which will be exemplified in the construction hereinafter set forth, 'and' the scope of their ap plicatlon will appear in the appended claims.

form of crusher embodying this inventionin a more practical form; Fig. 3 is a vertical section of the crushe shown in Fig. 2 on a larger scale,

Fig. 4 is a view in horizontal section on the plane indicated by the broken line fir-4 of Fig. 3, but on a smaller scale.

Fig. 5 shows partly in section and partly in elevation still another modification.

Referring now to the drawing, and to Fig. 1 in particular the crusher here illustrated comprises the relatively movable crusher members 5 and 6, the latter being shown as movably suspended within the former and operates as the head for deliver-. ing the crushing impact to the stone, rock,

ore, or other material fed into the receiving I opening of the crusher. The crusher member 5 is shown as the stationary or fixed member; while the crusher member 6 is suspended at 7 on the fixed spherical seat, within the outer or fixed member 5, in order that it may have universal movement and also gyrate when" necessary. These members are shaped as shownto provide converging conical surfaces between which the material to be crushed is fed and finally crushed as it is about to pass out at the discharge opena ing 8, which is a small annular clearance space between the converging surfaces adjacent their lower ends.

The suspended crusher member or head 6 mechanically considered is a conical pendulum suspended so that it is free to execute movement substantially in any direction in a plane transverse to the axis of symmetry, (i. e. where the am litude is small the movements may be considered as in a plane) and also to gyrate when necessary about its axisof symmetry. This crusherhead is actuated by a mechanism involving a rotating system which revolves at a relatively high angular velocity for imparting a harmonic movement of high periodicity to the head.

Th rotating system is hereshown as comprising the rotating element or shaft 9 rotatably supported by a bearing at 10 and adapted to be driven by any suitable prime mover (not shown in the interest of clearness). Secured on the end of the shaft 9 within the member 6 adjacent its lower end is a pulleylike element 11 which operates as an impeller for revolving an intermediate body 12 whose mass centre is eccentric to the axis of the rotating system. This intermediate body is here shown as spherical or ball shaped and serves as the means for trans mitting energy from the rotating system to the movable member 6 whose movements crush the material fed to the crusher.

The movable member or crusher head 6, as is obvious from the construction illustrated, operates as a restraining structure for the ball 12 which when rotated applies its centrifugal forces to the head; a harmonic movement is thus imparted to the crusher head from the rotating system whose fre quency is the revolutions per minute of the rotating system. The movement thus imparted compounds itselfwith that of the crusher head when moving freely as a conical pendulum to produce a resultant movement of the head yielding a quick succession of crushing impulses which are delivered by it to the material being crushed in the crusher. I

From the consideration of this movement from the standpoint of kinematics it is'apparent that the acceleration applied by the centrifugal force to the. head must lead the direction of radial displacement of this head toward the converging wall of the fixed member 5. The point of contact by the ball 12 against the interior wall of the head represents the point where this force is applied; hence, neglectingthe effects of friction etc., this point leads the point where the crusher head would make contact with the fixed member 5, (were its movement unrestrained) by an angle, probably in the neighborhood of 90 but less than 180 taken in the direction in which the rotating system revolves. The line of application of the force exerted by the ball is therefore substantially tangential with respect to the raceway and the ball 12 is accordingly relieved from substantially all the effects of reaction from the head during crushing operations tending to batter it back and forth, thereby avoiding any tendency to the jamming of the ball within the crusher head as well as to the indenting of the raceway and the deforming of the ball.

, In operation the ore or rock fed into the crusher, as a consequence of the rapidity with which the crusher head moves, is subjeoted chiefly to a shattering or impact elfect in addition to attrition; moreover, by reason of the high rate of recession and approach of thecrusher head to the fixed member at any particular point of the discharge open ing, the material between the crusher members does not have time to fall through such opening unless this material is smaller than the minimum size of this opening. In this connection it will also be perceived that the crusher head tends to describe a more or less well defined path, which in the case of the single ball described, is generally circular in shape and is limited rather sharply to a definite maximum determined by the kinematic constants of the system. As a consequence of this definite maximum move ment' the minimum size of the particles which pass through the crusher Will substantially be determined by the minimum size with which the discharge opening is designed. By suitably proportioning the discharge opening therefore, the machine can be adapted to crush the material to as fine or as coarse a size as desired.

Except when there is material being crushed between the crusher members or the discharge opening 8 ismade very narrow so that the material being crushed is substantially pulverized, the crusher head 6 moves throughout its path Without gyration about its axis of symmetry. When opening 8 is made sufiiciently small for pulverizing, the main circular movement is very constrained and the head will gyrate by reason of contact with fixed member, the direction of gyration being opposite to that of the rotating system. In practice it is found that with a speed of rotation of the rotating system of 3600 R. P. M., the rate of gyration, when the opening 8 is made sufficiently small for pulverizing may be from to 100 revolutions per minute, while if the opening is relatively large and the crusher is being used for crushing relatively coarse material, as distinguished from pulverizing, the rate of gyration may be 10 per minute or less.

Referring now to the embodiments shown in Figs. 2 and 3, 15 denotes a crusher member which is surmounted by the spider or frame 16; the latter supporting the tubular extension 17 having the spherical enlargement 18 thereon, from which is suspended the movable crusher member 20. To pro- Vide these relatively movable members with converging surfaces which mayalso be renular" member 21 and a lower supporting member 22 which in turn is held in place by the annular wedge 23 secured in place tension 17 is disposed the rotating system A posed in the housing 28 whose rotor 44 is v balls 46 against the inside of the movable by bolts 24 engaging with the member 15 for this purpose. .The movable member 20, in like manner has its lower end encased in the annular sleevemember 25 which is held 'in place by the large nuts 26 engaging with the "threaded formation 27 on the lower end of member 20. These bushing and sleeve members are preferably formed of hard metal so as to provide wearing surfaces with relatively long life.

The tubular extension '17 is enlarged at its .upper end into a housing 28 which is adjustably held in the spider 16. This housing slides in and is guided by ways 29 formed in r the hub 30 from which the legs of the spider 16 radiate. The housing 28 has a threaded formation 31 on its exterior with which the capstan nut 32 engages. This nut is shown as adapted for manual operation, to which end it is provided with handles 33 and turns and rides upon the hub 30.

The spherical enlargement 18 on the tubular extension 17 constitutes aball seat for supporting in pendent position the movable member 20 in a manner permitting of universal motion, and also permitting as in the form first described the gyration of member 20 when necessary. The suspension of the movable member 20 from the ball seat at 18 is accomplished by means of the bearing. members 35 secured in it and adapted to bear on and swivel upon the spherical enlar'gement at 18. These bearing members are in turn held in place by the nut 36 which engages with the upper end of member 20. Between the nut 36 and the tubular member 17 there is inserted an elastic member 37,

preferably of guttaercha, which has suflicient resilience to amp and prevent the setting up of oscillations of the pendulum body which may be due to its pendulum length. This elastic member is retained'in placeby means of the annular nut 38 en; 'ga ing with the upper end of nut 36. L ithin the housing 28 and the tubular ex which -actuates the movable member or head 20. This system comprises the tubular shaft 40 supported by and turning in the lower bearing shown at 41 and the upperbearing shown at 42. This shaft is represented as being revolved by the electric motor 43 dissecured to the shaft. At its lower end the shaft 40 has secured thereon the impeller member 45 (frequently termed a cage) which is here designed to impel one or more crusher member, a plurality of balls being provided if desired in order to multiply the centrifugal force applied to the head to'eifect crushing. The impeller 45 is shown as providing individual compartments 47 for the respective balls 46. The bills in the different horizontal levels of theimpeller are processes 47 having balls disposed therein, but

is also shown with emptyrecesses symmetri cally disposed in opposition with those having balls therein. This arrangement provides an impeller which is itself balanced dynamically so that there are no resultant forces in the rotating system to hammer or otherwise strain or cause wear upon the bearings 41 and 42.

The arrangement of balls 46 employed is here such that the average centre of mass for the set is eccentric to the axis of rotation so as to apply a resultant centrifugal force for producing -the movement of the movable crusher member. The arrangement shown however may be varied at will so long as the average mass centre of the set of balls employed is eccentric to the axis of rotation.

Themotor 43 for revolving the shaft 40 is preferably one adapted to impart a high rate of revolution, a two pole induction type of motor running on a sixty cycle source of alternating current being well adapted in pl'actice to give desired speeds of approximately 3600 R. P. M. Ventilation may -be provided for the motor employed by means of openings found in the housing 28, as those motor 43 with a central upstanding boss 51 arranged to permit the shaft 40 to pass upwardly therethrough. The boss 51 is enveloped by a'bell52 secured on and turning with the shaft40. This bell 52, when re- 'volving, serves to agitate the oil in the reservoir and draw it down over the boss into the casing 28 along the shaft 40 and from thence through the annular passage 53 from whence portion of the lubricant emerges by way of the radial passages 54 to lubricate the bear- The lubricant thus passing from the casing 'ings 35, the remainder of the lubricant in I the passage still passing downwardly to lubricate lower bearings 41 and the balls 46'.

28 ultimately collects in the bottom of the movable member 20 whereit is agitated by i the projecting tubular nozzle 55 of relatively fine bore which, by capillary action, institutes the upward movement of the lubricant into the interior of shaft40. This shaft is shown as provided with a filler 56 which is exteriorly cylindrical, to vfit within the bore ofthe' shaft 40, but has itself an upwardly into the reservoir at 50. This reservoir is closed by the cap 57 having the auxiliary cap 58. The lubricating system described may of course be varied to suit the design of different machines, a forced system of lubrication being at times preferable.

The operation of the crusherwhen crushing rock, stone, or other material is as follows: The material to be crushed is fed into the hopper shaped space between the converging surfaces of the crusher members 15 and 20. The motor which during crushing operations is rotated at a high angular velocity revolves shaft 40 and causes the impeller 45 to urge the balls 46 against the ball races interiorly of the crusher head with a centrifugal force of relatively largp magnitude which results in the above described movement of the head. The head in consequence takes up its main circular movement at a very rapid rate about the interior of the fixed crushing member executing a harmonic motion determined by the design properties and those of the rotating system resulting in a succession of quick crushing impacts imparted to the material being crushed. The use of the capstan nut 33 permits the head 20 to be raisedv or lowered at will and by this adjustment attain any desired size of crushed material from the crusher.

a It will be observed, that by avoiding the use of an eccentric for imparting motion to the crusher head, the lower bearing heretofore usually provided for the eccentric and its operating shaft is di'spensed with; thereby eliminating the friction incident to the .use of such bearing. ,The space below the crusher as" a consequence is left free and open foraccess to the crusher parts; for ex- .ample, should it be desired to-renew or repair the lower surface members, the open space thus provided may be utilized advantageously for, accommodating a portable work bench or carrier, as for instance a truck movable into or out of positionbeneath-the crusher.

The rapid circular and gyratory movement of the head 20,'resulting in very rapid vibratory movements of the head,als'o tends to break up any packing or clogging effect that may take place in the body of the material fed between the crusher members.

For the reasons above set forth, the crusher descrlbed has a large capacity or output, both with respect to the size of the machine and with respect to the power required for the operation thereof; a one horse power.

characteristics imposed both by its own V,

by the rotation of tirely enclosed within the suspended crusher member or head 59, the head being mounted seat or bearing 60 above the driving motor 61, both the motor and the spherical seat being carried by a stud 62 which is retained in place by a nut 63 screwed thereon and bearing upon a spider 64. This latter is supported by the fixed crusher member 65. The nut 63, as here shown for convenience, has the form of a worm wheel operated by a manually operated worm 66 which thus adjusts the vertical position of the stud and crusher head.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the language used in the following claims is intended to cover all of the generic and s ecific features of the invention herein escribed and all statements of the scope of the invention, which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a crusher, the combination with relatively movable crusher members, one of said crusher members being suspended within the other, of a rotating system, a balanced impeller secured to said system and revolving therewith, and an intermediate body having a mass center eccentric tothe axis of rotation, and adapted to be urged by said impeller in a closed path about said axis.

2. In a crusher, the combination with rel atively movable crusher members, one of said crusher members being supported withon a spherical in the other, of a rotating system, a prime, mover therefor, an impeller having symmetrically disposed recesses revolved by said system, and an intermediate body havin mass disposed in a recess at one side ofsai impeller, the movable crusher member being arranged to comprise a. restraining structure for said intermediate body impelled said system.

3. In acrusher, the combination with relatively movable crusher members, one of saidcrusher members being supported within the other, of a rotating system, a prime mover therefor, an impeller having recesses disposed in balancing relation therein,'and a ball disposed in a recess at one side'of saidimpeller, the movable crusher member being provided with raceways adapted to restrain said balls within prescribed limits when rotated by said system.

4. In a crusher, the combination with relatively movable crusher m'embers,-one of said crusher members being supported within the other, of a rotating system, an electric motor for revolving the same, an impeller having a plurality of diametrically oppositely disposed recesses formed therein, and intermediate bodies arranged in said recesses to have an average mass centre eccentric to the axis of rotation, the movable crusher members enveloping said impeller and provided with a restraining structure for limiting the outward movement of said bodies under the influence of the resultant centrifugal force.

5. A crusher comprising relatively movable crusher members, one of said members being suspended as a conical pendulum to have freedom of motion in a plane transverse to its axis .of symmetry, and an actuating mechanism for the suspended member having a means for developing centrifugal force and applying the same as the crushing impetus, said mechanism being supported independently of the suspended member at its point of suspension.

6. A crusher comprising relatively movable crusher members, one of said members beingsuspended as a conical pendulum to have freedom of motion in a plane transverse to its axis of symmetry, and an actuating mechanism having a. rotating system and means revolved thereby provided with a mass center eccentric tothe axis of revolution whereby a vibratory crushing move ment is produced in said suspended member, said mechanism being supported independently of said suspended member at its point of suspension.

7..A crusher comprising relatively movable crusher members one of said members being mounted to have freedom of motion within the other, means mounted to revolve around the axis of symmetry of the movable member and adapted to apply centrifugal force thereto and thereby cause the same to be oriented, and a prime mover for revolving said'means.

8. A crusher comprising relatively movable crusher members one of said members being provided with a universal bearing on which it is mounted to have movement within the other member, a shaft extending axially with respect to the axis of symmetry of the movable crusher member, an intermediate body eccentric to said shaft and adapted to transmit motion therefrom to the movable crusher member to 'eifect.harmonic movement thereof, and a motor directly connected to said shaft for rotating the same.

9. A. crusher comprising relatively movable crusher members one of said members being provided with a universal hearing at its upper port-ionon. which it is mounted to have movement within the other crusher member, and driving means above the lower end of the movable member and connected thereto interiorly thereof for effecting movement of the same whereby the space below the movable crusher member is left unobstructed by the driving means.

10. In a crusher, the combination with a vertical shaft, of an impeller mounted on said shaft, rolling bodies located eccentrically within said impeller, and a raceway having lateral freedom of motion and adapted to react against said bodies.

11. In a crush-er, the combination with a vertical shaft, of an impeller mounted on said shaft, rolling bodies located eccentrically within said impeller, a raceway having lateral freedom of motion and adapted to react against said bodies, and a movable crusher member arranged to support said raceway.

12. A gyratory crusher, comprising in combination, a crusher bowl, a crusher head mounted for gyratory movement within said bowl, means within said head adapted to engage the same to effect gyrato-ry movement thereof, driving means for rotating said head-engaging means about a movable axis, and a support for said means permitting the same to be moved outwardly into engagement with said head by centrifugal force,

13. A' crusher comprising an outer fixed member'and an inner member suspended to swing therein, means within said inner member mounted to rotate therein and centrifugally acting means operated thereby to cause said inner member to effect a gymtory crushing movement relatively to said outer member. g

14. A gyratory crusher comprising, in combination, a casing having an mner crushing wall, a crushing surface, a shaft for supporting the crushing surface to swing Within said crushing wall with crushing effect, an unbalanced rotatable weight supported to impart its gyratory movement to said crushing surface, and means for rotating said weight. y

In testimony whereof I aflix my signature:

BENJAMIN A. MITCHELL. 

